Desired outcomes for arthroscopic ligament reconstruction surgery are generally achieved by establishing the proper shape and placement of torn tissue. In a typical arthroscopic procedure, however, a cruciate footprint is often hidden from view by soft tissue, as well as remnant cruciate tissue. Such an arthroscopic procedure typically includes debriding the soft tissue and/or the remnant cruciate tissue to visualize the repair site, and establishing approach angles through portals located on the patient's skin. The reconstruction can then be accomplished by creating bone tunnels through the patient's femur and tibia. These bone tunnels are subsequently filled with a tendon graft, replicating the original damaged tissue.
The typical arthroscopic procedure described above has shortcomings, however, due at least in part to problems pertaining to the lack of visualization, the approach angles, and the shape of the tendon graft. Although the shape of the tendon graft is generally not round, that is often the shape of the reconstructed repair. Because the approach angles are generally not perpendicular to the skin surface, however, the portals located on the patient's skin are often visualized as being elliptical, making proper placement of the bone tunnels through the patient's femur and/or tibia difficult to achieve.
While performing arthroscopic ligament reconstruction surgery, a surgeon typically makes a small incision in a patient's skin covering the surgical site, e.g., a bone joint, to allow a surgical instrument(s) to be placed in the bone joint and manipulated through arthroscopic visualization. One such surgical instrument can be configured to operate in both a drilling mode and a cutting mode. The surgical instrument includes a shaft, and a drill bit portion having a conical, multi-blade configuration. The drill bit portion is configured to engage with the shaft, and to articulate between a “straight” position approximately parallel to the longitudinal axis of the shaft, and a “flip” non-parallel position relative to the longitudinal axis of the shaft. While operating in the drilling mode, the surgical instrument can be employed in an antegrade manner with the conical, multi-blade drill bit portion in the straight parallel position relative to the shaft's longitudinal axis. While operating in the cutting mode, the surgical instrument can be employed in a retrograde manner with the conical, multi-blade drill bit portion in the flip non-parallel position relative to the shafts longitudinal axis.
For torn knee anterior cruciate ligament (ACL) reconstruction, there has been an evolution in the anatomic femoral placement at the reconstructed ACL. One approach to achieving proper placement of the reconstructed ACL includes creating a tunnel from the outside to the inside (i.e., from the “outside in”) of the patent's femur. With this approach, a guide can be used to establish a desired path for the femoral tunnel, and a guidewire can be placed along the desired path. A trans-tibial approach may then be employed, in which the knee is flexed to about 90°, the guide is placed in the center of the tibial footprint, and a tunnel is drilled through the tibia and extending into the femur. Alternatively, a flexible and/or retrograde drill may be employed, or the patient's knee may be hyper-flexed to allow the femoral and tibial tunnels to be drilled independent of one another.
Still another approach may be employed, in which the femoral/tibial tunnels are drilled through an anterior medial portal. With this approach, a curved guide can be used to place a guidewire, and an appropriately sized reamer can be advanced over the guidewire to create a bone tunnel. Alternatively, the patient's knee can be hyper-flexed to allow straight line drilling of the bone tunnel. A retro-drill can also be assembled inside the bone joint, and the bone tunnel can then be drilled in a retrograde manner.